1. Preheat oven to 400°F and toss cubed squash with olive oil, salt, and pepper on a sheet pan. Roast 25–30 minutes until golden and tender.

2. Heat 2 tablespoons butter in a large pot over medium heat. Sauté chopped onion until translucent, about 5 minutes, then add minced garlic and cook 1 minute.

3. Add roasted squash and vegetable broth to the pot. Bring to a simmer and cook 10 minutes.

4. Carefully blend soup in batches until smooth, or use an immersion blender in the pot. Return to pot over low heat.

5. Stir in heavy cream, ground nutmeg, and cinnamon. Simmer 5 more minutes, adjust seasoning, then keep warm.

6. For croutons, heat griddle over medium heat. Butter one side of each bread slice, place buttered side down, top with cheddar, and cover with second slice, buttered side up.

7. Grill sandwiches 2–3 minutes per side until golden and cheese is melted. Let rest 1 minute, then cut into 1-inch cubes.

8. Ladle soup into bowls, top with cheddar croutons and optional pumpkin seeds, and garnish with fresh thyme.